Summary:

Plants or algae form the lowest level of the food web. At each link upward in a food web, only a small fraction of the matter consumed at the lower level is transferred upward, to produce growth and release energy in cellular respiration at the higher level. Given this inefficiency, there are generally fewer organisms at higher levels of a food web. Some matter reacts to release energy for life functions, some matter is stored in newly made structures, and much is discarded. The chemical elements that make up the molecules of organisms pass through food webs and into and out of the atmosphere and soil, and they are combined and recombined in different ways. At each link in an ecosystem, matter and energy are conserved.

Standards Alignment:

NGSS (HS-LS2-4) Use mathematical representations to support claims for the cycling of matter and flow of energy among organisms in an ecosystem. [Assessment boundary - Assessment is limited to proportional reasoning to describe the cycling of matter and the flow of energy.]

Overview of Resources:

Engage: In this crash course video, watch Hank introduce ecosystem ecology

Explore: Read the text and explore the interactive features in E. O. Wilson’s Life on Earth, Unit 7, Chapter 37, Section 3, The Living Web

Explore: Create your own food webs and check your work using this Food Web App from The University of Western Australia

Evaluate: Using Voice Thread, create a food web in an ecosystem of your choice. Include a minimum of 10 organisms to show the energy flow from producers to top-level consumers